Fe-g-PDEAEMA纳米复合微球的制备及性质研究

由聚N,N-二乙基胺基甲基丙烯酸乙酯(PDEAEMA)与铁纳米颗粒复合制得的纳米铁基复合材料。纳米铁微球表面钝化形成Fe3O4后,将多巴胺基引发剂修饰在Fe3O4的表面,通过表面引发原子转移自由基聚合(SI-ATRP)将DEAEMA单体聚合在修饰了多巴胺基引发剂的表面获得Fe-g-PDEAEMA复合微球。显微结果表明修饰PDEAEMA后,复合微球的分散性得到了一定的提高;XRD数据表明在纳米铁表面生成了一层Fe3O4壳。利用透光率测定研究了复合微球的p H敏感性,表明在酸性条件下悬浮性良好,在碱性条件下发生了沉降,复合微球具有p H敏感性。通过还原降解酸性大红染料,表明Fe-g-PDEAEM复合微球与纳米铁相比,其还原性有所提高,合成的Fe-g-PDEAEMA复合微球可用于氯代烃等氯化物污染的水体保护。     

聚多巴胺球支撑银纳米粒子制备无酶过氧化氢生物传感器

近年来,以聚多巴胺球支撑的纳米复合材料越来越受到人们的关注。聚多巴胺球有表面功能化基团如—OH、—NH_2等,决定了聚多巴胺球可以充当多种纳米复合材料的活性载体。利用聚多巴胺良好的还原性制备并负载银纳米粒子于聚多巴胺球表面,制备出的新型复合材料银纳米粒子-聚多巴胺球(以下简写为Ag@pdop)。Au修饰电极和银纳米粒子对过氧化氢的还原反应均具有很好的催化性能,利用两者特点将其复合制备修饰电极实现对H2O2的无酶传感,检测灵敏度达到了14.7μA/(mmol·L-1),检出限可达11.8μmol/L,线性范围0.2~6.0mmol/L,检测结果及抗干扰能力均令人满意。     

聚多巴胺球支撑银纳米粒子制备无酶过氧化氢生物传感器

近年来,以聚多巴胺球支撑的纳米复合材料越来越受到人们的关注。聚多巴胺球有表面功能化基团如—OH、—NH_2等,决定了聚多巴胺球可以充当多种纳米复合材料的活性载体。利用聚多巴胺良好的还原性制备并负载银纳米粒子于聚多巴胺球表面,制备出的新型复合材料银纳米粒子-聚多巴胺球(以下简写为Ag@pdop)。Au修饰电极和银纳米粒子对过氧化氢的还原反应均具有很好的催化性能,利用两者特点将其复合制备修饰电极实现对H2O2的无酶传感,检测灵敏度达到了14.7μA/(mmol·L-1),检出限可达11.8μmol/L,线性范围0.2~6.0mmol/L,检测结果及抗干扰能力均令人满意。     

基于金/巯基相互作用的功能分子在磁性高分子复合微球表面可控组装研究

建立了一种基于金纳米粒子与巯基相互作用的在磁性高分子复合微球表面高效组装功能分子的新方法.首先制备了粒径均一的介孔磁性纳米粒子簇(MSP),利用蒸馏沉淀技术在MSP上包覆一层―S―S―键交联的聚甲基丙烯酸壳层(P(MAA-Cy)),并将直径10~30 nm的金纳米粒子沉积在MSP@P(MAACy)复合微球表面,从而获得MSP@P(MAA-Cy)-Au NP复合微球.调控HAu Cl4的投料量可以控制金纳米粒子沉积数量和尺寸.利用金粒子和巯基之间的强相互作用,将巯基修饰的荧光分子快速可控组装在MSP@P(MAA-Cy)-Au NP微球上.作为模型示范,实现了一次在MSP@P(MAA-Cy)-Au NP微球上快速固定单种或多种功能分子,为即时、高效、定量在功能微球(靶向药物载体等)上修饰功能分子提供了一种可选择的解决方案.     

二氧化钛接枝聚(苯乙烯-二乙烯苯)/马来酸酐多孔纳米复合微球的制备及表征 二氧化钛接枝聚(苯乙烯-二乙烯苯)/马来酸酐 多孔纳米复合微球的制备及表征

中孔聚合物微球, 由于具有大的比表面积、小的孔径和孔容, 并有与外界环境介质相通的多孔孔道等特点而被应用于化妆品活性物和药物的缓释载体, 以提高药物及化妆品活性物的安全性和使用效率. 在早期的工作中, 我们报道了聚苯乙烯-二乙烯苯[P(St- DVB)]多孔聚合物微球的制备及其在化妆品活性物缓释中的应用[4]. [P(St-DVB)]多孔聚合物微球用于化妆品活性物的负载取得了较好的缓释效果, 但是此种多孔聚合物微球在负载如Pasorl-1789类易光解的活性组分时, 由于聚合物本身的透明性, 当在紫外线等强光照射下, 易光解的活性物就会发生分解, 最终导致失去活性作用, 因此纯的聚合物微球对易光解的活性物起不到良好的保护和缓释. 纳米二氧化钛由于具有良好的紫外吸收和折射能力及无毒等优点而广泛地应用于化妆品的物理防晒剂. 因此, 将纳米二氧化钛均匀地覆盖在多孔聚合物微球的表面可以在聚合物微球表面形成一道阻挡紫外线的屏障, 有效防止负载于多孔聚合微球内部的活性物的分解. 本文通过开环反应方法制备了二氧化钛接枝聚(苯乙烯-二乙烯苯)/马来酸酐中孔复合微球. 首先用氨基基团对纳米二氧化钛粒子表面进行修饰, 一方面防止其团聚, 另一方面使纳米粒子具有与聚合物微球产生共价键合的基团. 然后对多孔聚合物粒子表面进行马来酸酐修饰, 使其在保持原有的多孔形貌的基础上产生可与纳米粒子表面氨基开环反应的马来酸酐基团. 制得的多孔纳米复合微球经红外光谱、扫描电镜、透射电镜、X光衍射能谱及紫外分光光度计等表征, 结果表明, 纳米复合微球表面均匀地覆盖了纳米二氧化钛粒子, 复合粒子比纯聚合物粒子和未经修饰的二氧化钛粒子具有更好的紫外吸收效果. 将制得的复合微球用于对活性物Parsol 1789 (一种化妆品活性组分, 见光易氧化)的负载和缓释结果表明, 纳米复合多孔微球对负载于多孔网络中的活性物具有屏蔽紫外防止氧化和缓释作用.     

二氧化钛接枝聚(苯乙烯-二乙烯苯)/马来酸酐多孔纳米复合微球的制备及表征

中孔聚合物微球,由于具有大的比表面积、小的孔径和孔容,并有与外界环境介质相通的多孔孔道等特点而被应用于化妆品活性物和药物的缓释载体,以提高药物及化妆品活性物的安全性和使用效率.在早期的工作中,我们报道了聚苯乙烯-二乙烯苯[P(St-DVB)]多孔聚合物微球的制备及其在化妆品活性物缓释中的应用[4].[P(St-DVB)]多孔聚合物微球用于化妆品活性物的负载取得了较好的缓释效果,但是此种多孔聚合物微球在负载如Pasorl-1789类易光解的活性组分时,由于聚合物本身的透明性,当在紫外线等强光照射下,易光解的活性物就会发生分解,最终导致失去活性作用,因此纯的聚合物微球对易光解的活性物起不到良好的保护和缓释.纳米二氧化钛由于具有良好的紫外吸收和折射能力及无毒等优点而广泛地应用于化妆品的物理防晒剂.因此,将纳米二氧化钛均匀地覆盖在多孔聚合物微球的表面可以在聚合物微球表面形成一道阻挡紫外线的屏障,有效防止负载于多孔聚合微球内部的活性物的分解.本文通过开环反应方法制备了二氧化钛接枝聚(苯乙烯-二乙烯苯)/马来酸酐中孔复合微球.首先用氨基基团对纳米二氧化钛粒子表面进行修饰,一方面防止其团聚,另一方面使纳米粒子具有与聚合物微球产生共价键合的基团.然后对多孔聚合物粒子表面进行马来酸酐修饰,使其在保持原有的多孔形貌的基础上产生可与纳米粒子表面氨基开环反应的马来酸酐基团.制得的多孔纳米复合微球经红外光谱、扫描电镜、透射电镜、X光衍射能谱及紫外分光光度计等表征,结果表明,纳米复合微球表面均匀地覆盖了纳米二氧化钛粒子,复合粒子比纯聚合物粒子和未经修饰的二氧化钛粒子具有更好的紫外吸收效果.将制得的复合微球用于对活性物Parsol1789(一种化妆品活性组分,见光易氧化)的负载和缓释结果表明,纳米复合多孔微球对负载于多孔网络中的活性物具有屏蔽紫外防止氧化和缓释作用.     

聚多巴胺修饰金纳米花的可控制备及在光热治疗中的应用

采用无模板法制备了金纳米花, 其形状与粒径大小可以通过改变反应温度和还原剂抗坏血酸的用量来调控; 然后, 通过多巴胺的表面原位聚合反应制备了聚多巴胺修饰的金纳米花, 以提高其在近红外区的吸收能力及生物相容性. 采用透射电子显微镜(TEM)、 紫外-可见吸收光谱(UV-Vis)和纳米粒度/Zeta电位仪等对金纳米花和聚多巴胺修饰金纳米花的形态、 粒径和光学特性进行了表征; 通过傅里叶变换红外吸收光谱(FTIR)分析证明聚多巴胺修饰成功; X射线衍射(XRD)分析结果表明, 聚多巴胺修饰前后金纳米花的晶体结构未变; 最后, 采用噻唑蓝(MTT)法体外评价了聚多巴胺修饰金纳米花的细胞毒性. 研究结果表明, 反应温度越低, 金纳米花表面分支结构越丰富, 以0 ℃为最佳反应温度; 还原剂抗血酸的用量越高, 金纳米花粒径越小; 金纳米花粒径在60~100 nm范围内可调, 最大吸收波长为575~650 nm. 经聚多巴胺修饰后, 金纳米花的最大吸收波长发生了显著红移(>80 nm), 近红外区的吸收范围显著扩大. 通过调控多巴胺溶液浓度, 可将金纳米花表面聚多巴胺层的厚度控制在8~14 nm. 在808 nm激光辐照下, 聚多巴胺修饰金纳米花溶液可迅速升温至57 ℃. 此外, 细胞实验结果表明, 聚多巴胺修饰后金纳米花的细胞毒性更低. 用其对HeLa肿瘤细胞进行光热治疗后, 细胞存活率仅为10%. 因此, 聚多巴胺修饰金纳米花作为光热试剂在肿瘤治疗领域具有潜在的应用前景.     

以碳微球为核的金纳米壳球体的制备

通过水热合成法制备了单分散碳微球, 并以此单分散碳微球为核, 利用其表面修饰的银纳米粒子作为种子, 进一步还原制备了以碳微球为核、以金为壳的金纳米壳(Nanoshell)球体. 通过透射电子显微镜和紫外可见吸收光谱对其形态以及光谱性质进行了表征. 研究结果表明, 采用该种方法制备出来的碳微球具有良好的单分散性, 表面修饰简便快捷, 利用碳微球为核制备的金纳米壳球体尺寸可控, 在近红外范围内有强吸收. 实验结果证明该方法是制备金纳米壳球体的一种有效新方法.     

单分散聚苯乙烯微球的表面皱纹化

首先制备了不同粒径的未交联的单分散聚苯乙烯(PS)微球;而后通过离子溅射技术在PS微球表面沉积了一层均匀光滑的铂(Pt)壳层,得到了PS-Pt核壳结构的复合微球;最后借用溶剂溶胀法诱导微球表面起皱的发生,从而制备了表面带有皱纹微结构形貌的PS微球.系统考察了微球表面Pt层厚度(t)、微球粒径(D)、溶剂组成(即溶胀度)等因素对球面起皱和皱纹形貌的影响,获得了球面皱纹周期与Pt层厚度的指数关系;结合理论分析了其起皱行为,实验结果与理论分析相吻合.此外,将表面起皱与表面等离子体刻蚀技术相结合,实现了表面带有纳米点状凸起与皱纹复合微结构形貌的PS微球的可控制备.     

以纳米材料为基质的激光解吸离子化质谱成像研究进展

基质辅助激光解吸离子化质谱(MALDI-MS)作为一种常规的软电离分析表征方法,被广泛应用于多肽、蛋白质、核酸等生物大分子的分析。近些年,基于纳米粒子和纳米结构表面的MALDI-MS成像技术(MALDI-MSI)凭借其样品制备简单、不需标记、高通量等优点,在组织结构研究、药物代谢、刑事侦查等领域表现出良好的应用前景。本文总结了MALDI-MSI纳米基质材料的研究进展,并对其发展及应用进行了展望。     

Matrix-assisted laser desorption/ionization mass spectrometry of polysaccharides with 2',4',6'-trihydroxyacetophenone as matrix

So far, there have been only a few matrices reported for detection of polysaccharides with molecular weight higher than 3000 Daltons by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). In this work, we found that 2',4',6'-trihydroxyacetophenone (THAP) is a good matrix for MALDI time-of-flight MS analysis of polysaccharides with broad mass range. Large polysaccharides, dextrans, glycoproteins and polysialic acids have been successfully detected by MALDI-MS with THAP as matrix.     

Matrix-assisted laser desorption/ionization mass spectrometry of taxanes

Taxanes are biologically active compounds that have been extensively used in pharmacology for their powerful anticancer properties. High specificity and low level sensitivity for analysis of these compounds have been obtained with reversed-phase high-pressure liquid chromatography/mass spectrometry (RP-HPLC/MS), but the number of applications of matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) for low molecular weight analytes is rapidly growing. A new MALDI-MS approach for the rapid screening of a variety of taxanes and a tandem mass spectrometric (MS/MS) analysis of the most important and diagnostic taxane fragmentation pathways are proposed. A solid-phase extraction method followed by preliminary quantification is also reported.     

基体辅助激光解吸/电离质谱测定小相对分子质量物质的方法进展

MALD I-MS分析具有高灵敏度、高分辨率、高质量准确度、制样快速、操作简单及高通量等优点,具有使各种不同类型物质离子化的能力。目前已广泛应用于化学、化工、材料、环境、地质、能源、刑侦、药物、生命科学等领域中。MALD I-MS最早主要用于分析各种生物大分子及聚合物。近年     

Direct surface analysis of fungal species by matrix-assisted laser desorption/ionization mass spectrometry

In this study various methods of sample preparation and matrices were investigated to determine optimum collection and analysis criteria for fungal analysis by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). Intact spores and/or hyphae of Aspergillus niger, Rhizopus oryzae, Trichoderma reesei and Phanerochaete chrysosporium were analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS). The fungal samples were applied to the MALDI sample target as untreated, sonicated, or acid/heat treated samples, or blotted directly from the fungal culture with double-stick tape. Ferulic acid or sinapinic acid matrix solution was layered over the dried samples and analyzed by MALDI-MS. Statistical analysis showed that simply using double-stick tape to collect and transfer to a MALDI sample plate typically worked as well as the other preparation methods, and required the least sample handling.     

Extraction and characterization of adenovirus

A new methodology for the extraction and characterization of proteins from Coomassie-stained sodium dodecylsulfate polyacrylamide gel electrophoresis using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) has been described. The utility of this methodology was demonstrated in the characterization of adenovirus proteins. The key steps in the extraction and destaining process involve washing the excised band with a combination of solvents that include 10% acetic acid, acetonitrile, methanol, and formic acid:water:isopropanol mixture. By using this procedure, we determined adenovirus proteins with molecular weights ranging from 10,000 to 110,000 Da by MALDI-MS, obtaining a detection limit of approximately 6 pmol. Parallel experiments were successfully carried out to analyze adenovirus proteins from Cu-stained gels. It was observed that increase in laser intensity resulted in significant improvements in the quality of MALDI mass spectra for the analysis of inefficiently destained proteins from Cu-stained gels.     

Molecular weight determination of hyaluronic acid by gel filtration chromatography coupled to matrix-assisted laser desorption ionization mass spectrometry.

An analytical approach has been described for the molecular weight characterization of enzymatically degraded hyaluronic acid (HA). The approach involved the combined use of aqueous gel filtration chromatography (GFC) with matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS). Microfractions were collected across an eluting peak from the chromatography system, followed by mass spectrometric analysis of these narrow fractions. The molecular mass determined by MALDI-MS and the signal obtained from the chromatography established a calibration curve for other hyaluronic acid samples analyzed by this GFC system. Results of one HA sample were obtained from both the calibration curve and direct fraction-by-fraction MALDI-MS analysis, and comparison of these results showed reasonable agreement. In contrast, molecular weights resulted from external calibration using dextran and pullullan standards showed drastically different numbers. Therefore, the GFC-MALDI-MS approach is a reliable method for the molecular weight characterization of polydisperse polysaccharides for which suitable calibration standards are unavailable for conventional GFC analysis.     

Coupling microchip electrophoresis with MALDI-TOF-MS based on a freezing technique

A freezing technique protocol was proposed for coupling microchip electrophoresis with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry(MALD1-TOF-MS).The microfluidic flow was frozen immediately after electrophoresis on microfluidic chip and the separated analyte molecules were kept in their zone pattern in the electrophoresis.Then,the frozen-chip was lyophilized and sent into TOF-MS instrument as a MALDI target,and the analyte molecules in the microfluidic channels were subjected to analysis by mass spectrometry.This approach could eliminate sample cross-contamination, providing a new interface for microchip electrophoresis and MALDI-MS.     

人红细胞20S蛋白酶体的蛋白质组学表征及不同来源20S蛋白酶体异质性的研究

通过整合差速离心和非变性聚丙烯酰胺凝胶电泳(native-PAGE)技术,建立了能有效分离20S蛋白酶体(20S core particle,CP)的方法.与传统纯化方法比较,此方法具有经济、快速的特点,并且能够对不同组织细胞来源的CP进行分离.利用本方法对人红细胞来源的CP亚基进行了2-DE分离和MALDI-TOF/TOF MS鉴定.结果显示,可鉴定出33个具有不同相对分子量和等电点的蛋白点,此数量远远多于CP亚基的14种.此外,利用非变性/变性十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(native/SDS-PAGE)技术,比较了来源于酵母、小鼠肝脏、人红细胞、人胰腺癌细胞系SW1990和PANC-1的CP及其亚基在电泳行为方面的差异,进行了蛋白酶体异质性初探.     

Polyamine co-matrices for matrix-assisted laser desorption/ionization mass spectrometry of oligonucleotides.

The analysis of oligonucleotides using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) has led to the investigation of the use of matrix additives (i.e., co-matrices) to help improve the poor spectral quality commonly observed during the analysis of this class of compounds. The use of certain matrix additives in MALDI-MS has been investigated previously, and these additives have been shown to enhance the desorption/ionization efficiency of oligonucleotides during the MALDI experiment. Specifically, amine bases, such as piperidine, imidazole, and triethylamine, have been shown to improve mass spectral quality as assessed by improved molecular ion resolution and increased molecular ion abundance. These improvements occur due to competition between the oligonucleotide and the co-matrix for protons generated during the MALDI event. Co-matrices with proton affinities near or above the proton affinities of the nucleotide residues serve as proton sinks during the desorption/ionization process. In this work, we have investigated the use of polyamines as co-matrices for MALDI mass spectrometric analysis of oligonucleotides. Spermine tetrahydrochloride, spermine, spermidine trihydrochloride, and spermidine were evaluated for their effectiveness at enhancing the mass spectral quality of oligonucleotides analyzed using MALDI-MS. The solution-phase pK( b) values and the gas-phase proton affinities of these polyamines were determined, and it was found that the polyamines appear to be more basic than the monofunctional amines investigated previously. The mass spectral data shows that spermidine and spermine are extremely effective co-matrices, yielding improved molecular ion resolution and molecular ion abundances. The spermine co-matrices are more effective than the spermidine co-matrices, but adduction problems with the spermine co-matrices limits their overall utility. In general, polyamine co-matrices are found to be more effective than monofunctional amine co-matrices at improving the mass spectral data obtained during MALDI-MS of oligonucleotides.     

Infrared laser post-ionization of large biomolecules from an IR-MALD(I) plume

A two-infrared laser desorption/ionization method is described. A first laser, which was either an Er:YAG laser or an optical parametric oscillator (OPO), served for ablation/vaporization of small volumes of analyte/matrix sample at fluences below the ion detection threshold for direct matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). A second IR-laser, whose beam intersected the expanding ablation plume at a variable distance and time delay, was used to generate biomolecular ions out of the matrix-assisted laser desorption (MALD) plume. Either one of the two above lasers or an Er:YSGG laser was used for post-ionization. Glycerol was used as IR-MALDI matrix, and mass spectra of peptides, proteins, as well as nucleic acids, some of which in excess of 10(5) u in molecular weight, were recorded with a time-of-flight mass spectrometer. A mass spectrum of cytochrome c from a water ice matrix is also presented. The MALD plume expansion was investigated by varying the position of the post-ionization laser beam above the glycerol sample surface and its delay time relative to the desorption laser. Comparison between the OPO (pulse duration, tau(L) = 6 ns) and the Er:YAG laser (tau(L) approximately 120 ns) as primary excitation laser demonstrates a significant effect of the laser pulse duration on the MALD process.